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ba2f1a67 FG |
1 | From 40d641241a5399afc93d4eb75d8794f72fe3c0fb Mon Sep 17 00:00:00 2001 |
2 | From: Wolfgang Bumiller <w.bumiller@proxmox.com> | |
3 | Date: Wed, 21 Dec 2016 15:37:20 +0100 | |
4 | Subject: [PATCH] cgroup, cpuset: add cpuset.remap_cpus | |
5 | MIME-Version: 1.0 | |
6 | Content-Type: text/plain; charset=UTF-8 | |
7 | Content-Transfer-Encoding: 8bit | |
8 | ||
9 | Changes a cpuset, recursively remapping all its descendants | |
10 | to the new range. | |
11 | ||
12 | Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com> | |
13 | Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> | |
14 | --- | |
15 | include/linux/cpumask.h | 17 ++++++++++++++++ | |
16 | kernel/cpuset.c | 54 +++++++++++++++++++++++++++++++++++++++---------- | |
17 | 2 files changed, 60 insertions(+), 11 deletions(-) | |
18 | ||
19 | diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h | |
20 | index 59915ea..f5487c8 100644 | |
21 | --- a/include/linux/cpumask.h | |
22 | +++ b/include/linux/cpumask.h | |
23 | @@ -514,6 +514,23 @@ static inline void cpumask_copy(struct cpumask *dstp, | |
24 | } | |
25 | ||
26 | /** | |
27 | + * cpumask_remap - *dstp = map(old, new)(*srcp) | |
28 | + * @dstp: the result | |
29 | + * @srcp: the input cpumask | |
30 | + * @oldp: the old mask | |
31 | + * @newp: the new mask | |
32 | + */ | |
33 | +static inline void cpumask_remap(struct cpumask *dstp, | |
34 | + const struct cpumask *srcp, | |
35 | + const struct cpumask *oldp, | |
36 | + const struct cpumask *newp) | |
37 | +{ | |
38 | + bitmap_remap(cpumask_bits(dstp), cpumask_bits(srcp), | |
39 | + cpumask_bits(oldp), cpumask_bits(newp), | |
40 | + nr_cpumask_bits); | |
41 | +} | |
42 | + | |
43 | +/** | |
44 | * cpumask_any - pick a "random" cpu from *srcp | |
45 | * @srcp: the input cpumask | |
46 | * | |
47 | diff --git a/kernel/cpuset.c b/kernel/cpuset.c | |
48 | index 7e78cfe..ff5ff3a 100644 | |
49 | --- a/kernel/cpuset.c | |
50 | +++ b/kernel/cpuset.c | |
51 | @@ -462,7 +462,8 @@ static void free_trial_cpuset(struct cpuset *trial) | |
52 | * Return 0 if valid, -errno if not. | |
53 | */ | |
54 | ||
55 | -static int validate_change(struct cpuset *cur, struct cpuset *trial) | |
56 | +static int validate_change(struct cpuset *cur, struct cpuset *trial, | |
57 | + int remap) | |
58 | { | |
59 | struct cgroup_subsys_state *css; | |
60 | struct cpuset *c, *par; | |
61 | @@ -470,11 +471,13 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial) | |
62 | ||
63 | rcu_read_lock(); | |
64 | ||
65 | - /* Each of our child cpusets must be a subset of us */ | |
66 | - ret = -EBUSY; | |
67 | - cpuset_for_each_child(c, css, cur) | |
68 | - if (!is_cpuset_subset(c, trial)) | |
69 | - goto out; | |
70 | + if (!remap) { | |
71 | + /* Each of our child cpusets must be a subset of us */ | |
72 | + ret = -EBUSY; | |
73 | + cpuset_for_each_child(c, css, cur) | |
74 | + if (!is_cpuset_subset(c, trial)) | |
75 | + goto out; | |
76 | + } | |
77 | ||
78 | /* Remaining checks don't apply to root cpuset */ | |
79 | ret = 0; | |
80 | @@ -937,11 +940,15 @@ static void update_cpumasks_hier(struct cpuset *cs, struct cpumask *new_cpus) | |
81 | * @cs: the cpuset to consider | |
82 | * @trialcs: trial cpuset | |
83 | * @buf: buffer of cpu numbers written to this cpuset | |
84 | + * @remap: recursively remap all child nodes | |
85 | */ | |
86 | static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, | |
87 | - const char *buf) | |
88 | + const char *buf, int remap) | |
89 | { | |
90 | int retval; | |
91 | + struct cpuset *cp; | |
92 | + struct cgroup_subsys_state *pos_css; | |
93 | + struct cpumask tempmask; | |
94 | ||
95 | /* top_cpuset.cpus_allowed tracks cpu_online_mask; it's read-only */ | |
96 | if (cs == &top_cpuset) | |
97 | @@ -969,11 +976,25 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, | |
98 | if (cpumask_equal(cs->cpus_allowed, trialcs->cpus_allowed)) | |
99 | return 0; | |
100 | ||
101 | - retval = validate_change(cs, trialcs); | |
102 | + retval = validate_change(cs, trialcs, remap); | |
103 | if (retval < 0) | |
104 | return retval; | |
105 | ||
106 | spin_lock_irq(&callback_lock); | |
107 | + if (remap) { | |
108 | + rcu_read_lock(); | |
109 | + cpuset_for_each_descendant_pre(cp, pos_css, cs) { | |
110 | + /* skip empty subtrees */ | |
111 | + if (cpumask_empty(cp->cpus_allowed)) { | |
112 | + pos_css = css_rightmost_descendant(pos_css); | |
113 | + continue; | |
114 | + } | |
115 | + cpumask_copy(&tempmask, cp->cpus_allowed); | |
116 | + cpumask_remap(cp->cpus_allowed, &tempmask, | |
117 | + cs->cpus_allowed, trialcs->cpus_allowed); | |
118 | + } | |
119 | + rcu_read_unlock(); | |
120 | + } | |
121 | cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed); | |
122 | spin_unlock_irq(&callback_lock); | |
123 | ||
124 | @@ -1250,7 +1271,7 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs, | |
125 | retval = 0; /* Too easy - nothing to do */ | |
126 | goto done; | |
127 | } | |
128 | - retval = validate_change(cs, trialcs); | |
129 | + retval = validate_change(cs, trialcs, 0); | |
130 | if (retval < 0) | |
131 | goto done; | |
132 | ||
133 | @@ -1337,7 +1358,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, | |
134 | else | |
135 | clear_bit(bit, &trialcs->flags); | |
136 | ||
137 | - err = validate_change(cs, trialcs); | |
138 | + err = validate_change(cs, trialcs, 0); | |
139 | if (err < 0) | |
140 | goto out; | |
141 | ||
142 | @@ -1596,6 +1617,7 @@ static void cpuset_attach(struct cgroup_taskset *tset) | |
143 | typedef enum { | |
144 | FILE_MEMORY_MIGRATE, | |
145 | FILE_CPULIST, | |
146 | + FILE_REMAP_CPULIST, | |
147 | FILE_MEMLIST, | |
148 | FILE_EFFECTIVE_CPULIST, | |
149 | FILE_EFFECTIVE_MEMLIST, | |
150 | @@ -1728,7 +1750,10 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of, | |
151 | ||
152 | switch (of_cft(of)->private) { | |
153 | case FILE_CPULIST: | |
154 | - retval = update_cpumask(cs, trialcs, buf); | |
155 | + retval = update_cpumask(cs, trialcs, buf, 0); | |
156 | + break; | |
157 | + case FILE_REMAP_CPULIST: | |
158 | + retval = update_cpumask(cs, trialcs, buf, 1); | |
159 | break; | |
160 | case FILE_MEMLIST: | |
161 | retval = update_nodemask(cs, trialcs, buf); | |
162 | @@ -1845,6 +1870,13 @@ static struct cftype files[] = { | |
163 | }, | |
164 | ||
165 | { | |
166 | + .name = "remap_cpus", | |
167 | + .write = cpuset_write_resmask, | |
168 | + .max_write_len = (100U + 6 * NR_CPUS), | |
169 | + .private = FILE_REMAP_CPULIST, | |
170 | + }, | |
171 | + | |
172 | + { | |
173 | .name = "mems", | |
174 | .seq_show = cpuset_common_seq_show, | |
175 | .write = cpuset_write_resmask, | |
176 | -- | |
177 | 2.1.4 | |
178 |